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<span id="Division-of-poly_005fints"></span><div class="header">
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Next: <a href="Other-poly_005fint-arithmetic.html" accesskey="n" rel="next">Other <code>poly_int</code> arithmetic</a>, Previous: <a href="wi-arithmetic-on-poly_005fints.html" accesskey="p" rel="prev"><code>wi</code> arithmetic on <code>poly_int</code>s</a>, Up: <a href="Arithmetic-on-poly_005fints.html" accesskey="u" rel="up">Arithmetic on <code>poly_int</code>s</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html" title="Index" rel="index">Index</a>]</p>
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<span id="Division-of-poly_005fints-1"></span><h4 class="subsection">10.4.3 Division of <code>poly_int</code>s</h4>

<p>Division of <code>poly_int</code>s is possible for certain inputs.  The functions
for division return true if the operation is possible and in most cases
return the results by pointer.  The routines are:
</p>
<dl compact="compact">
<dt>&lsquo;<samp>multiple_p (<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
<dt>&lsquo;<samp>multiple_p (<var>a</var>, <var>b</var>, &amp;<var>quotient</var>)</samp>&rsquo;</dt>
<dd><p>Return true if <var>a</var> is an exact multiple of <var>b</var>, storing the result
in <var>quotient</var> if so.  There are overloads for various combinations
of polynomial and constant <var>a</var>, <var>b</var> and <var>quotient</var>.
</p>
</dd>
<dt>&lsquo;<samp>constant_multiple_p (<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
<dt>&lsquo;<samp>constant_multiple_p (<var>a</var>, <var>b</var>, &amp;<var>quotient</var>)</samp>&rsquo;</dt>
<dd><p>Like <code>multiple_p</code>, but also test whether the multiple is a
compile-time constant.
</p>
</dd>
<dt>&lsquo;<samp>can_div_trunc_p (<var>a</var>, <var>b</var>, &amp;<var>quotient</var>)</samp>&rsquo;</dt>
<dt>&lsquo;<samp>can_div_trunc_p (<var>a</var>, <var>b</var>, &amp;<var>quotient</var>, &amp;<var>remainder</var>)</samp>&rsquo;</dt>
<dd><p>Return true if we can calculate &lsquo;<samp>trunc (<var>a</var> / <var>b</var>)</samp>&rsquo; at compile
time, storing the result in <var>quotient</var> and <var>remainder</var> if so.
</p>
</dd>
<dt>&lsquo;<samp>can_div_away_from_zero_p (<var>a</var>, <var>b</var>, &amp;<var>quotient</var>)</samp>&rsquo;</dt>
<dd><p>Return true if we can calculate &lsquo;<samp><var>a</var> / <var>b</var></samp>&rsquo; at compile time,
rounding away from zero.  Store the result in <var>quotient</var> if so.
</p>
<p>Note that this is true if and only if <code>can_div_trunc_p</code> is true.
The only difference is in the rounding of the result.
</p></dd>
</dl>

<p>There is also an asserting form of division:
</p>
<dl compact="compact">
<dt>&lsquo;<samp>exact_div (<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
<dd><p>Assert that <var>a</var> is a multiple of <var>b</var> and return
&lsquo;<samp><var>a</var> / <var>b</var></samp>&rsquo;.  The result is a <code>poly_int</code> if <var>a</var>
is a <code>poly_int</code>.
</p></dd>
</dl>




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